Detection of tallow adulteration in cow ghee by derivative spectrophotometry

CONTEXT: Ghee is a widely consumed dairy product in India and that prepared from cow milk is mentioned in ayurvedic texts as an ingredient of many formulations/additive as well. Detection of cow ghee adulteration with vegetable oils/fats and animal body fats is a key concern. Indicated values for commonly used parameters to differentiate pure and adulterated ghee materials are many a times overlapping. Among reported techniques, ultraviolet fluorescence and paper chromatography technique are not that much sensitive while other methods require sophisticated instrumental facilities (such as gas chromatography, mass spectrometry) and costly analytical processes. AIMS: The present paper deals with a promising spectroscopic method to determine the tallow adulteration in cow ghee. MATERIALS AND METHODS: Ghee and tallow (taken in chloroform) as such and mixed in different proportions were scanned by spectrophotometer and their second order spectra were analyzed. RESULTS: The value of the ratio of the absorbance of peaks at about 238 nm and 297 nm steadily decreases with the increasing proportion of tallow. This decrease shows consistent linearity suggesting its applicability for quantitative estimation of tallow in cow ghee. CONCLUSION: The developed derivative spectroscopic method is a rapid, sensitive, cost-effective method for detection of tallow adulteration in cow ghee.